The invention relates to a strand guide in a continuous casting plant having frame or stand parts, lying opposite each other in pairs and being connected by drawing anchors for accommodating the strand guide rollers, and a relief means having a pressure medium cylinder.
When operational disturbances cause a stand-still of the continuous casting plant during casting, the already greatly cooled strand may get stuck when conveyed, whereby strand guide parts may be damaged or a rupture of the strand may be caused.
A known strand guide (German Offenlegungsschrift No. 2,062,792) has a relief means for detaching the strand guide rollers from the strand, consisting of two wedges arranged with their inclined faces toward each other. One of the wedges is displaceable along a slide path relative to the other one in the horizontal direction. The wedge angles are bigger than the angles of friction so that the two wedges slide upon each other when the displacement path is not limited. As a result the strand guiding rollers arranged on both sides of the strand and facing each other can be moved apart. The displacement path of the two wedges is limited in this construction by a further wedge that is adjustable by means of a pressure medium cylinder which is withdrawn in case of a disturbance, thus freeing the displacement path. During casting the pressure medium cylinder must always be actuated, otherwise the ferrostatic pressure of the strand would press the three wedges apart. An undesired loss of pressure thus also causes a yielding of the strand guide parts and consequently the strand may bulge. A further disadvantage of the known relief means is that the wedges, after an actuation of the relief means for freeing the strand, must be made to slide upon one another and on the partly open slide paths by a force to be created by the strand, and this is complicated by pollution or grit along the slide path and the influence of temperature on the shape of the path during the rough casting operation.